ií
V i
i
38. Grammonema :
a
f n
39. Raphoneis ;
(a. et b. Ehombus ;
c. mediterranea).
40. Doiypliora = Bhaphoneis stipitata.
Frustula quadrangula, a
fronte (a. b. c.) lanceolata
(a), elliptica (b) vel late
elliptica et utroque polo
late rotundata (c), nodulo
centrali d e stitu ta , striis
vel costis transversis, ubi
adsunt, medio vitta vel
area longitudinali inter-
ruptis.
41. Synedra:
(Ulna).
Frustula fronte (a) lineari-lanoeolata,
striis transversis parallelis linea longitudinali
medio in te rru p tis , nodulo
centrali annuliformi ; latere lineari-
rectangula, striis marginalibus abbreviatis,
nodulo centrali nullo.
42. Asterionella:
(a . formosa; b. Ealfsii).
Frustula e basi plus minus incrassata linearia, fasoiolatim vel radiatim
concreta.
Fam. VII. Amphipleureae.
43. Ainphipleura; (pellucida).
a) Frustula fusiformia carin ata , nodulo centrali nullo ; b) sectio transversa,
utroque latere oarinis prominentibus.
44. Raphidogloea :
(micans).
Frustula Ampbipleurae dense aggregata, in fila radiantia disposita et
muco matrioali involuta; b. 0. fronte.